Connector for high amperage applications

ABSTRACT

A unitary connector particularly suitable for high amperage applications is disclosed. It provides a high density of smaller conductor connections per length of connector. In spite of the high density, the connection of any one conductor can be adjusted without disturbing the connection of any other conductor. The connector greatly facilitates visual inspection of all connections for confirmation of the completeness and security of each connection. The connector body can be made from metal extrudate, and current passing through the integral connector does so without passing across butting interfaces between elements within the connector assembly.

United States Patent 1 [111 3,732,530 Linn et al. 1 May 8, 1973 [54] CONNECTOR FOR HIGH AMPERAGE Dl95,623 7/1963 Leonardo ..339 272 R x APPLICATIONS 3,399,270 8/1968 Stoddard ..l74/90 Dl95,623 7/1963 Leonardo ..26/1 [75] Invemms R'chard 'Nmthbrmk; 2,909,751 10/1959 Speck ..339/l98 Gerald J. Shea, Buffalo Grove, both of 7 Primary Examiner-Marvin A. Champion [73] Assignee: Underwriters Safety Device Comis ant Examine -Robert A. Hafer pany, Chicago, Ill. Attorney-Joseph P. O'Halloran [22] F1ledz Jan. 31, 1972 [57] ABSTRACT [21] Appl' 221318 A unitary connector particularly suitable for high amperage applications is disclosed. It provides a high 1 /27 R density of smaller conductor connections per length of [51] Int. Cl. ..H01r 9/00 connector, In spite of the high density, the connection of Search R, E, of any one conductor can be adjusted without disturb- 339/198 198 193 198 198 1 ing the connection of any other conductor. The con- 198 198 198 Pr 198 198 14 R, nector greatly facilitates visual inspection of all con- 272 272 272 272 A, 263 R, 263 B1 motions for confirmation of the completeness and 263 263 263 242; 74/71, 90 security of each connection. The connector body can be made from metal extrudate, and current passing [56] References C'ted through the integral connector does so without passing UNITED STATES PATENTS across butting interfaces between elements within the connector assembly. 3,399,270 8/1968 Stoddard l74/90 3,594,710 7/1971 Stanback ..339/198 N 9 Claims, 6 Drawing Figures PATENTEDMAY ems 3.732530 SHEET 2 BF 2 CONNECTOR FOR HIGH AMPERAGE APPLICATIONS This invention relates to distribution of electrical power to a plurality of branch circuits and particularly pertains to a unitary connector for electrically connecting a plurality of conductors to a common potential. The connectors of the present invention are suitable for use as feeder bars, neutral junction connections, and the like, and power distribution systems involving relatively high amperage, such as for example, 100 amps and higher.

This invention is an improvement over the invention disclosed in copending application Ser. No. 221,975 filed Jan. 31, 1972 by Richard L. Linn for Connector For High Amperage Applications, both applications being owned by a common assignee.

It is an object of the present invention to provide a unitary electrical connector which is relatively inexpensive to manufacture, which is suitable for use in high amperage applications, and which does not involve the use of butting interfaces within a connector assembly across which the current would pass.

It is another object of the present invention to provide such a unitary connector which cannot only accommodate relatively large ground or supply conductors, but moreover can accommodate a relatively high density of smaller conductors per length of connector face for feeding a plurality of individual loads.

Another object of the present invention is to provide a connector which greatly facilitates visual inspection of the unit after all electrical connections are made, for confirmation that each of the electrical connections is complete and secure.

It is a further object of the present invention to provide a connector which not only can accommodate a high density of smaller connections per length of connector face, but also permits adjustment of the securing means for any individual conductor without disturbing the securing means for connecting any other conductor connected thereto.

These and other objects are all achieved in accordance with the present invention which is described herein and with the aid of the accompanying drawings in which:

FIG. 1 is a perspective view of a preferred embodiment of the present invention;

FIG. 2 is an end view taken toward the end of the connector which is shown at the left of FIG. 1;

FIG. 3 is a top view of the connector shown in FIG. 1;

FIG. 4 is an end view of the end opposite that shown in FIG. 2;

FIG. 5 is a cross sectional view taken approximately along the lines 5--5 of FIG. 2; and

FIG. 6 is a top view of an alternative embodiment of the present invention.

In FIG. 1 a unitary metal connector in accordance with the present invention is generally indicated by the numeral 10. Connector 10 comprises a unitary integral segment 11 of metal extrudate, securing means for electrically connecting a plurality of conductors thereto, and other important structural features. Connector 10 is secured by securing means, such as threaded fasteners 12, to an insulating support (not shown), and conventionally is installed within a suitable box or cabinet (not shown because conventional).

In the illustrated embodiment a large conductor 16 is secured within a substantially circular opening 18 which passes through a first enlarged portion 20 of connector l0. Conductor 16 is secured therein by compression by means of a set screw 22 (indicated by broken lines 24 in FIG. 1), which can be threaded within opening 26 which, in turn, communicates with opening 18.

First enlarged portion 20 of connector block 11 is connected to a second enlarged portion through a relatively narrow central bridging portion 28. The space or gap between enlarged portions 20 and 27 is sufficiently great to provide a line of sight over the top of portion 20 to the junction between bridge 28 and portion 27. This line of sight forms an angle of at least 10, and more preferably at least 20 with the adjacent part of portion 27. (See angle a, FIG. 5).

A number of smaller conductors 30, 31, such as for example, feeder wires, are receivable in respective openings 32, 33 which pass through second enlarged portion 27. As used herein, the numeral 30 is intended to indicate any of the conductors which are secured within one of the lower openings 32 (as viewed in FIG. 1) and 31 is intended to include any of the conductors affixed in any of the upper openings 33.

The conductors 30 of the lower tier are secured by compression in the respective openings 32 by adjustment of respective set screws 34. Conductors 31 are secured by compression in their respective openings 33 by adjustment of respective set screws 35. Thus, when secured, all conductors are pressed directly against the integral metal body 11 of the connector 10. Set screws 34, 35 are threaded through respective tapped openings 36, 37 which are positioned to direct the respective set screws across the respective conductorreceiving openings 32, 33.

It is noted that openings 32, 33 pass entirely through section 27. Although it is not essential that passthrough openings be employed, and blind openings of sufficient depth can be employed, it is preferred that all conductor-receiving openings pass entirely through section 27. In such an embodiment in which passthrough openings 32, 33 are employed, the completed connector system can be visually inspected for confirmation that the conductors in each of the respective openings have been inserted a sufficient distance to provide a complete and secure electrical connection. When pass-through conductor-receiving openings are employed, and when conductors are inserted sufficiently to cause the ends thereof to extend at least to the inner sides 38, 39 of enlarged portion 27, the completed assembled unit can be visually inspected by glancing down along sides 38, 39, to visually confirm the proper insertion of each of the conductors. When blind" conductor-receiving holes are employed, it is not uncommon for inadequate or incomplete insertion of the conductor to be encountered. In the high amperage applications to which the present invention primarily directs itself, the use of multiple strand cable is conventional. When such cable is inserted in the conductorreceiving openings, there is a tendency for some of the strands to jam against burrs, threads, etc., and give the impression that the conductor is completely inserted past the set screw. Tightening of the set screw under such circumstances may provide a very insecure electrical connection. On the other hand, in accordance with the preferred embodiment of the present invention in which pass-through openingsare utilized and sufficient spacing is provided between the enlarged lateral portions 20, 27 to permit visual inspection, it will be immediately apparent whether the individual cables are completely and properly inserted for secure electrical connection. This visual inspection is particularly facilitated as a consequence of the novel structural relationships between the elements of the present invention, and these relationships are now discussed in further detail.

The second enlarged portion 27 has a cross section (as seen in FIG. 5) resembling stairs, and comprises steps 40, and 42. It is noted that, as shown in FIG. 5, the steps 40, 42 are so positioned that successive steps descend as the first enlarged portion 20 is approached along a line drawn through steps 40, 42 toward the enlarged portion 20 such as for example, along a line proceeding in a direction from the left of FIG. 3 through second enlarged portion 27 toward first enlarged portion 20.

Openings 32, 33 pass through side face 44 and thence through walls 38, 39, respectively. Thus first step 40 includes a side face 38 through which openings 32 pass, and a top surface 46 through which openings 36 pass. The second higher step 42 includes a side face 39 through which openings 33 pass and a top surface 50 through which openings 37 pass. Additional steps can be provided if desired. Thus openings 32 pass through the entire width of surfaces 50 and 46, whereas openings 33 pass through portion 27, the width of surface 50.

Thus in the embodiment illustrated in FIGS. 1, 2 and 3, a single large conductor 16 approaches connector along a line from a first direction, and smaller conductors 30, 31 enter conductor 10 along parallel lines from the opposite direction, and current can pass directly through the connector segment 11 without passing through butting interfaces such as those which would be encountered in a non-unitary connector comprising a number of assembled elements.

As a consequence of the positioning of enlarged portions 20, 27 on opposite sides of narrow central bridging portion 28, and providing openings along the sides 44, 51 of the connector 10 to accomodate and secure the conductors and by arranging the connections for the smaller conductors along the steps 40, 42, relatively high density smaller connector input is achieved along the length of enlarged portion 27. Moreover as a result of this configuration, all the set screws 22, 34, 35 and threaded fasteners 12 are accessible from the same direction (i.e., from the top as viewed in FIG. 5) and this provides considerable convenience and facilitates safety during the course of installation or servicing of the connector connections or the distribution system. Moreover, as a consequence of these spacings between enlarged portions and 27 and as a consequence of the arrangement of the present invention in which steps 40, 42 ascend in the direction away from the enlarged portion 20, and in combination with the pass-through openings 32, 33, two major advantages are achieved. First of all, visual inspection by glancing along surfaces 38, 39 readily confirms whether or not conductors 30, 31 are'completely and securely secured. The staggering of the steps in the direction away from enlarged portion 20 provides very large line of sight angles with surface 39, and the surfaces of any additional steps, thus affording an even better view of the secured conductor. Secondly, because of the particular configuration of the steps, the particular set screws 34, 35 which secure any particular conductors 30, 31 can be adjusted without disturbing the set screws which secure any other conductors 30, 31. This greatly increases the convenience of making changes, and facilitates safety during the course of installation, or servicing.

In the preferred illustrated embodiments, all conductors enter the connector 10 through parallel lines into two opposite sides of the connector 10. However, the connecting means for the large conductors 16 could be arranged to accept conductors approaching from different directions, e.g., from the bottom, but this would involve changing the direction of approach of tools for adjustment of conductor-securing means.

In the embodiment illustrated in FIG. 1 six smaller conductors 30, 31 are accomodated along a length of extrudate which is not quite twice the diameter of the large conductor 16. As indicated above, more steps (not shown) which are substantially identical to steps 40, 42 can be provided adjacent step 42, in which case still more smaller conductors could be accomodated by a connector having the same length.

In the embodiment illustrated in FIG. 6, a greater length of metal extrudate 56 is employed to provide a connector 55 which is suitable for higher amperage applications even through it has a cross section which is substantially identical to that shown in FIG. 5. Connector 55 comprises a first enlarged portion 57, a central narrow bridging portion 59 and a second enlarged portion 61. These and other elements are similar to the corresponding elements in the first described embodiment. For example, openings 63 are provided in the central bridging portion 59 to accommodate fasteners, for example, threaded fasteners 12 or rivets (not shown), to secure connector 55 to an insulating support (not shown because conventional). Large conductors 64 are admitted through openings 65, which are equivalent to openings 18 in the first described embodiment, and are secured therein by compression by set screws 67. Smaller conductors 69 are received in passthrough openings 70 corresponding to openings 32, 33 and are secured therein by set screws 71.

The embodiment illustrated in FIG. 6 is particularly useful for very high amperage applications. For example, for very high applications, instead of utilizing extremely large diameter conductors, which are difficult to pull, bend and install, it is more convenient to use a number of relatively smaller large cables which are easier to pull, bend and install, and yet which provide in aggregation the same current carrying capacity as the one extremely large diameter conductor. One of the individual smaller large cables is indicated in FIG. 6 by the numeral 64.

In the embodiment shown in FIG. 6 the conductor 55 can accommodate four such large conductors 64- and 27 smaller conductors 69.

The unitary metal piece 11 from which conductor 10 is manufactured is a length of metal extrudate having a cross sectionshownin FIG. 3. The depth of the bridge portion 28, 59 is chosen to amply accommodate anticipated current even though one or more passages 52, 63 are provided in bridge portion 28, 59, respectively, to accommodate fasteners. In the preferred embodiments a metal extrudate is utilized, and the structural elements corresponding to first enlarged portions 20, 57, bridging portions 28, 59 and second enlarged portions 27, 61 are automatically produced during the extrusion. The extrudate metal segment after appropriate hardening treatment, if desired, is cut into appropriate lengths and holes are drilled and tapped as desired. Alternately, the holes can be drilled and tapped before the larger segments of extrudate are cut into operating segments 11, and segments 56 from which connector 55 is made.

Although any conducting solid metal can be used to make the conductor of the present invention, preferred metals are those metals having a tensile strength greater than about 35,000 psi and a yield strength greater than about 25,000 psi. It is unnecessary to use an expensive material such as highly conductive silver in accordance with the present invention. Copper or aluminum can be employed, and other solid conducting metals can be used. A most preferred metal, however, is an aluminum alloy identified as AA 6061. This is a heat-hardenable extrudable aluminum alloy having approximately the following constituents in addition to aluminum.

silicon 0.40.8% (nominally 0.6%) iron less than 1% copper 0. l 5-0.4% (nominally 0.25%) manganese 0.15% max.

magnesium 008-1 .2% (nominally chromium 0. l 50.35% (nominally 0.25%) nickel none zinc 0.25% max.

titanium 0.15% max.

others 0.05% max.

Physical characteristics of these and other alloys are described in Metals Handbook, Eighth Edition, Volume I, Properties and Selection, published by the American Society for Metals (See page 917 for description of Aluminum 6061). The preferred Aluminum 6061 is that metal which has been heat treated to provide a hardness identified as T-6. This metal has a yield strength of 37,000 psi and a tensile strength of 42,000 psi. Consequently, even though the electrical volume conductivity of this metal is only 40 percent IACS, the physical characteristics of this alloy, particularly the high strength and low cold flow, are believed to be factors contributing to its outstanding success when used in the connector of the present invention.

In illustrated embodiments of the present invention the enlarged side portions 20, 27 and 57, 61 are connected by relatively thin bridging portions 28 and 59 respectively, near the base thereof. These bridging portions 28, 59 can be eliminated, and the connector 10 secured to an insulating support by means of threaded fasteners, etc., extending through the insulating support into the bottom of connector 10. However, it is much more preferable to provide the narrow bridging portion since several additional advantages accrue as a result. For example, the presence of the gap above the bridging portion 28 or 59 between enlarged portions and 27, or between enlarged portions 57, and 61, respectively, combined with the use of pass-through openings 18, 32, 33, 64, 70, assists the installer in visually confirming complete insertion of the conductors 16, 30, 31 within their respective securing openings 18, 32, 33. Thus, upon insertion of conductors 16, 30, 31 into their respective securing openings, until the respective conductor is visible at walls 38, or 78 above bridge portion 28 or 59, respectively, provides confirmation of the positioning of the respective smaller conductor that the necessary secure and complete electrical connection is made. Visual inspection of the completeness and security of the connection of the larger wires is also facilitated in the same way.

In general, the structural relationships and spacings of the preferred connector of the present invention are such that the line of sight over the top inner edge of first enlarged portion 20, 27 receiving the large conductor forms an angle of at least 10 and preferably more than 20 with the bottom of the nearest wall of the second enlarged portion (angle a, FIG. 3).

It will be appreciated that all of the laterally extending planes formed by the body 11, 56 such as for example, inner sides 38, 78 and sides 44, 48, which form vertical planes, and also horizontally extending surfaces such as, for example, top surfaces 46, 50, and all the other laterally extending surfaces of the body, extend the entire width of the body, encountering no other transverse structural elements of body 11, 56. Thus the topography or external surfaces of the general cross section of the body 11, 56, is substantially constant from end to end, except of course for the conductorreceiving and set screw-receiving openings.

We claim:

1. A unitary connector comprising: an integral body portion consisting of a single piece of solid metal having two ends and being shaped such that the topography of the general cross section of the body is the same from end to end, and in which said general cross section comprises first and second laterally positioned enlarged portions, said first and second enlarged portions being joined near the bases thereof by an integral relatively thin bridging portion, whereby adjacent opposing sides of said first and second enlarged portions are spaced apart from each other, said cross section having a shape such that steps are provided in said second enlarged portion, said steps being ascending in the direction away from said first enlarged portion; said first enlarged portion comprising first recess means for axially receiving a large conductor through one side of said body, and first securing means for compressing said large conductor transversely against said body within said recess means; said second enlarged portion including a plurality of second recess means for axially receiving respective smaller conductors perpendicw larly through another side of said body, and second securing means for compressing said respective smaller conductors transversely against said body within said second recess means, said second recess means comprising sets of recesses passing through respective parallel faces of said steps, and said second securing means passing transversely to said conductors through respective tops of said steps.

2. The connector of claim 1 in which said first and second recess means are parallel and enter said body from opposite sides of said body, and wherein said recess means comprise channels passing through said respective enlarged portions into the space above said bridge and between said enlarged portions, and wherein said first and second enlarged portions are spaced apart a sufficient distance such that a line of sight over the top edge of said first enlarged portion and extending to the juncture of the thin bridging portion and the adjacent opposing side of the second enlarged portion forms an angle of at least 10 with opposing side.

3. The unitary connector of claim 2 in which said line of sight passing over the top of the first enlarged portion forms an angle greater than with said opposing side of said second enlarged portion.

4. A connector of claim 1 in which said first enlarged portion includes a plurality of first recess means and first securing means for receiving and securing a plurality of respective large conductors.

5. A unitary connector particularly suitable for high amperage applications comprising: an integral body consisting of a single piece of solid metal having two ends and a cross section with uniform external shape the entire width of said body between said ends, said body comprising first and second enlarged lateral portions connected by a relatively narrow integral bridging portion disposed between the bases of the lateral portions whereby opposing sides of said first and second lateral portions are spaced apart; first recess means for receiving a large conductor, and first securing means for compressing said large conductor in said first recess means, said recess means and securing means being positioned in said first enlarged lateral portion of said body; said second enlarged portion being shaped to include at least a portion thereof which has a cross section in the form of steps wherein said steps are ascending in the direction away from said first enlarged portion, and wherein a first surface of the steps is parallel with said opposing side of said first enlarged portion, and a second surface of the steps is in a plane which is transverse to the steps first surface; said second recess means comprising a plurality of pass-through recesses passing completely through said second enlarged portion, said pass-through recess being sized for receiving smaller conductors, said pass-through recesses opening in the first surfaces of said steps, and said second securing means passing transversely to said first respective recesses through said second surface of said steps; and wherein a line of sight drawn over the top of the first enlarged portion to the juncture of the bridging portion and the first surface of the adjacent step forms an angle of at least 10 with said first surface of said adjacent step.

6. The connector of claim 5, wherein all the recess means are parallel and pass through their respective enlarged portions and open into the space between the enlarged portions.

7. The connector of claim 5 wherein the first enlarged portion comprises a plurality of said recess means and said securing means for receiving and securing a plurality of respective larger conductors.

8. The connector of claim 5 wherein at least one opening passes through said bridging portion, said opening being sized to receive a fastener for securing said body to an insulating support.

9. The connector of claim 5 in which said securing means comprises set screws, and in I which said set screws enter said body from the same direction which is transverse to the base of the connector. 

1. A unitary connector comprising: an integral body portion consisting of a single piece of solid metal having two ends and being shaped such that the topography of the general cross section of the body is the same from end to end, and in which said general cross section comprises first and second laterally positioned enlarged portions, said first and second enlarged portions being joined near the bases thereof by an integral relatively thin bridging portion, whereby adjacent opposing sides of said first and second enlarged portions are spaced apart from each other, said cross section having a shape such that steps are provided in said second enlarged portion, said steps being ascending in the direction away from said first enlarged portion; said first enlarged portion comprising first recess means for axially receiving a large conductor through one side of said body, and first securing means for compressing said large conductor transversely against said body within said recess means; said second enlarged portion including a plurality of second recess means for axially receiving respective smaller conductors perpendicularly through another side of said body, and second securing means for compressing said respective smaller conductors transversely against said body within said second recess means, said second recess means comprising sets of recesses passing through respective parallel faces of said steps, and said second securing means passing transversely to said conductors through respective tops of said steps.
 2. The connector of claim 1 in which said first and second recess means are parallel and enter said body from opposite sides of said body, and wherein said recess means comprise channels passing through said respective enlarged portions into the space above said bridge and between said enlarged portions, and wherein said first and second enlarged portions are spaced apart a sufficient distance such that a line of sight over the top edge of said first enlarged portion and extending to the juncture of the thin bridging portion and the adjacent opposing side of the second enlarged portion forms an angle of at least 10* with opposing side.
 3. The unitary connector of claim 2 in which said line of sight passing over the top of the first enlarged portion forms an angle greater than 20* with said opposing side of said second enlarged portion.
 4. A connector of claim 1 in which said first enlarged portion includes a plurality of first recess means and first securing means for receiving and securing a plurality of respective large conductors.
 5. A unitary connector particularly suitable for high amperage applications comprising: an integral body consisting of a single piece of solid metal having two ends and a cross section with uniform external shape the entire width of said body between said ends, said body comprising first and second enlarged lateral portions connected by a relatively narrow integral bridging portion disposed between the bases of the lateral portions whereby opposing sides of said first and second lateral portions are spaced apart; first recess means for receiving a large conductor, and first securing means for compressing said large conductor in said first recess means, said recess means and securing means being positioned in said first enlarged lateral portion of said body; said second enlarged portion being shaped to include at least a portion thereof which has a cross section in the form of steps wherein said steps are ascending in the direction away from said first enlarged portion, and wherein a first surface of the steps is parallel with said opposing side of said first enlarged portion, and a second surface of the steps is in a plane which is transverse to the step''s first surface; said second recess means comprising a plurality of pass-through recesses passing completely through said second enlarged portion, said pass-through recess being sized for receiving smaller conductors, said pass-through recesses opening in the first surfaces of said steps, and said second securing means passing transversely to said first respective recessEs through said second surface of said steps; and wherein a line of sight drawn over the top of the first enlarged portion to the juncture of the bridging portion and the first surface of the adjacent step forms an angle of at least 10* with said first surface of said adjacent step.
 6. The connector of claim 5, wherein all the recess means are parallel and pass through their respective enlarged portions and open into the space between the enlarged portions.
 7. The connector of claim 5 wherein the first enlarged portion comprises a plurality of said recess means and said securing means for receiving and securing a plurality of respective larger conductors.
 8. The connector of claim 5 wherein at least one opening passes through said bridging portion, said opening being sized to receive a fastener for securing said body to an insulating support.
 9. The connector of claim 5 in which said securing means comprises set screws, and in which said set screws enter said body from the same direction which is transverse to the base of the connector. 